Commutating electric machine



Patented May 6, 1-924.

UNITED STATES KANTABO'NOBUHARA, OE HYOGO-KEN, JAPAN.

COMMUTATING ELECTRIC MACHINE.

Application led July 26, `1922. Serial No. 577,576.

To all whom it 'may concern:

Be it known that KANTARO NOBUHARA, a subject of the Empire of Japan, residing at Nishinomiya, Mukogun, Hyogo-ken, Japan, has invented certain new and useful Improvements in Commutating Electric Machines; and he does hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements of a commutating electric machine, comprising an annular chamber surrounding a part of the surface of a commutator, and means to jet a cooling liquid with insulating properties upon the surrounded part of the commutator from the said annular chamber. It has for its object to cool the commutator effectively in order to get a large current density in the segment bars of the commutator.

The accompanying drawing shows a part of a motor embodying .this invention, in which Fig. 1 is a part sectional elevation of the commutator-end of a motor, and

F ig. 9. is an end view of the same part showing a part sectional elevation on line Il-II of Fig. 1.

In the drawing 1 is a part of a motor cas ing in which the working parts of the motor are enclosed. The commutator 2, which is integral with the rotor 3, extends out of the casing, and brushes -l are provided on the outer part of the commutator as is clearly shown in the drawing.

A. ring 5 made of insulating material is firmly fixed on ythe periphery of the commutator at such a position that it revolves inside the casing at a little distance from the wall. The function of this ring is to diffuse the cooling liquid by means of its centrifugal force, which liquid might get out of the casing along the surface of the commutator if the ring is not provided thereon.

Between the rotor und the ring, there is an annular chamber 6 provided inside the casing surrounding the surface of the commutator. The chamber consists of a hollow cast iron ring rmly fixed to the casing, and a plurality of passages 8 are provided axially throughout the ring. There is a little clearance left between the surface of the commutator and the inner surface of the ring, and a ring 9 made of insulating material is fixed on each side of the inner end of the ring 7, so as to make a little annular space 10 around the commutator. y l

rlhe annular space l0 communicates with the annular chamber 6 byway of 'passages 11, and with a circulating pump of any suitable type, such as that conventionally indicated at P, by way of a pipe 12.

The operation of the parts above described is as follows lllhen the motor revolves a liquid with ins'ulating quality as well as good cooling effect, such as transformer oil, is supplied into the annular chamber 6 by means of the pump. Then the liquid gets into the space 10 passing through the passages 11 and jets upon the surface of the commutator. The heat generated in the commutator is now absorbed by the cooling liquid, which then flows axially along the surface of the comniutator and diffuses itself by centrifugal force. The heated liquid deposits in the bottom of the casing and is taken out of the casing by means of the pump P which directs it again into the chamber 6 after it is cooled down.

In this invention, the commutator is effectively cooled so that the temperature rise of the commutator is comparatively low, and consequently, large current density in the commutator bars may be available.

lVhat I claim is 1. A commutating electric machine, comprising an annular chamber surrounding a part of the peripheral surface of a commutator, and means to direct a cooling liquid with insulating properties upon the surrounding part of the commutator from the said annular chamber.

2. A commutating electric machine, comprising an annular chamber surrounding a part of the peripheral surface of a commutator with an annular space provided between the surface of the commutator and the inner surface of the said chamber said chamber and space communicating with each other by way of passages, and means to di rect a cooling liquid with insulating properties upon the surrounded part of the commutator from the said chamber by way of said space.

3. A commutating electric machine, comprising an annular chamber surrounding a part of the peripheral surface of a commutator, with an annular space provided between the surface of the commutator and the inner surface of thel said Chamber by insulating "properties upon vthe surrounded part of 'the eomrnutator from tle'said annu- 15 lar chamber', and a ring made of insulating material fixedupon the oommutator in order to diffuse the liquid by Centrifugal force, which liquid might get out of the casing along the surface of the commutator.

20 In LteSt'imony whereof I hereunto affix my `signature in the presence of two Witnesses.

KANTARO NOBUHARA. Witnesses: 'W. CHILHRAH, 4

K; Tono. 

